As the demand for crude oil increases, there is a need for alternative sources of oil and improvements to current methods for procuring oil. Although there is significant oil in the United States, much of it is heavy oil which has yet to be efficiently and successfully obtained. Heavy oil is viscous and does not flow easily, resulting in very low recovery of the resource. There has been some success in significantly decreasing the viscosity of the heavy oil, but current methods are limited by the depth from surface of the heavy oil, as well as cost and efficiency of recovery methods.
The most popular process of heavy oil recovery at depths less than 2,000 feet below ground level is the injection of surface-generated steam. In this process, steam is pumped from the surface into an oil bearing formation through an injection well. The heat from the steam is transferred to the oil through condensation, conduction and convection. This reduces the oil viscosity and allows the oil to flow more easily into the production well for extraction. One example of a steam injection technique is described in U.S. Pat. No. 3,482,630 hereby fully incorporated by reference.
Alkaline flooding is another process used to recover medium to heavy oil where an alkaline solution is injected from the surface into an oil bearing formation containing an acidic crude oil. Most medium and heavy oils are acidic. As discussed in U.S. Pat. No. 4,813,483, hereby fully incorporated by reference, the chemical reaction between the injected alkaline and the acidic crude oil forms surfactants which reduce the interfacial tension between the oil and the water and allows for enhanced oil recovery.